碩士 / 國立臺灣大學 / 環境工程學研究所 / 105 / The algal blooms in lakes and reservoirs caused by eutrophication bring about series of water quality and environmental problems. Microcystis, a group of common bloom-forming cyanobacterial species, is of significant concern during the occurrence of eutrophication worldwide. The ability of forming colonies helps on Microcystis’ vertical migration, nutrient storage, and defense against predation. Therefore, such characteristic is believed to be the main reason for Microcystis to dominate over other phytoplankton in the thermally stratified lakes or reservoirs. Factors and mechanisms abiotic or biotic affecting the aggregation of colonies are not clearly identified and studied.
In this study, we applied two possible allelochemicals, glyoxylic acid and calcium chloride, in the water to observe their effects on the aggregation of Microcystis cells and water quality. Laboratory cultured Microcystis aeruginosa, died in two days due to the destructive irradiation of high intensity of light. Laboratory cultured algae cannot endure drastically change of environmental conditions. By using algae collected in the field, two chemicals retarded the growth rate of algae, especially glyoxylic acid at high concentration. However, no significant change of colony size was observed in treatments for both chemicals. Colony size distributions were ranging from 30 to 70 μm for five different conditions. And colony radii of the two treatments with simultaneous addition of two chemicals were smaller than those of other treatments.
Moreover, there have been some shortages in the application of glyoxylic acid as eutrophication controller. Glyoxylic acid is an organic compound. Pouring it in the reservoirs will cause the decrease of pH value and damage the water quality and ecosystem. Although calcium chloride tends to make particles bigger, we still need more study before applying calcium into reservoirs to control the growth of Microcystis.
| Identifer | oai:union.ndltd.org:TW/105NTU05515034 |
| Date | January 2017 |
| Creators | Meng-Ju Hsiao, 蕭孟儒 |
| Contributors | Shian-chee Wu, 吳先琪 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 42 |
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